1. Field of the Invention
The present invention relates to automotive and fixed alternators, and more specifically to a small slip ring end (SRE) frame to accommodate a heavy duty rectifier assembly.
2. Description of the Related Art
The current trend for better fuel economy and efficiency is leading to increased demand on automotive electrical systems. With the increased draw on the automotive electrical systems it becomes necessary to supply higher output alternators that can meet the additional electrical demand on the battery and higher loads experienced by the alternator.
High output popular small frame alternators on vehicles and machinery used in automotive, industrial, agricultural and marine industries have a high rate of failure due to higher operating temperatures typically caused by continuous higher charging rate, lack of heat dissipation through rectifier heat sinks and diodes, insufficient cooling, i.e., air exchange/air flow, through the alternator and associated components, and debris buildup that limits cooling air flow. Failures are often evidenced as “burnout”, and are predominantly found in the rectifier assembly.
Larger SRE frames used in larger framed alternators generally accommodate a more robust rectifier assembly having larger heat sinks and employing an electronic technology known as “twinning” wherein a twin diode is placed in parallel with each of a positive side three phase rectifying diode.
Thus three positive side diodes, one for each phase, are twinned with 3 additional diodes, resulting in a total of 9 diodes, three for the three phases on the negative side and 6 for the three phases on the positive side. When adequately cooled, the 9 diode large heat sink rectifier increases current capacity and durability for a variety of applications while to a large degree, eliminating the aforementioned “burnout” problem.
Yet the small framed alternator remains in many applications in which there is not enough physical space to mount a larger framed alternator. For example, there are many vehicles and other machinery in operation today that use the popular high output small frame alternators. However there exist no small frame alternator SRE frames that can physically accommodate and adequately cool the aforementioned larger rectifier assemblies available in larger framed alternators.
Thus, a slip ring end frame to accommodate a heavy duty rectifier assembly solving the aforementioned problems is desired.